Background: Noncoding RNAs (ncRNAs), including microRNA (miRNA) and long noncoding RNA (lncRNA), are functional and non-protein coding RNA molecules. miRNAs are small ncRNAs of 18-23 nucleotides, whereas LncRNAs are longer than 200 nucleotides and were recently recognized as a class of genomic regulatory molecules and reported in various species. Nonetheless, their physiological functions have not been elucidated. Methods: In order to investigate a possible involvement of ncRNAs in salt-sensitive hypertension, we performed ncRNA sequencing and transcriptome analysis in Dahl salt-sensitive rats and Lewis rats. The pathway analysis were used to understand the biological roles of differently expressed ncRNAs. Results: Following ncRNA sequencing, 591 transcripts were defined as mature miRNAs and 2636 transcripts as lncRNAs. Of these, 9 miRNA were mapped to candidate chromosomal regions (chromosome 1, 10, and 12), previously reported to be involved in salt-sensitive hypertension. Differential expression was detected for 3 of these miRNAs (miR-150-5p, miR-7a-5p, miR-21-5p) (fold up/down ≥ 1.2, q < 0.05). However, only one lncRNA (XLOC_081666) encoded by the candidate region of chromosome 1 showed no difference. In contrast, 10 miRNAs (miR-1b, miR-221-3p, miR-300-3p, miR-411-5p, miR-184, miR-205, miR-129-5p, miR-741-3p, miR-379-5p, miR-138-5p) and 5 lncRNAs (XLOC_102471, XLOC_047839, XLOC_253638, XLOC_778532, XLOC_1029112), located in other regions, showed significant differential expression (fold up/down ≥ 2.0, q < 0.05). The pathway analysis showed that Wnt and MAPK signaling pathways are associated with the targets of detected miRNAs and metabolic pathways are associated with the possible targets of detected lncRNAs. Although expression levels of target mRNAs in these pathways showed no differences between Dahl salt-sensitive and Lewis rats, it is likely that effects of a single ncRNA on mRNA expression are subtle and may exhibit different response to salt intake. Conclusions: Our results demonstrate the probable implication of miRNAs and lncRNAs in salt-sensitive hypertension. This new finding may contribute to the exploration of candidate factors involved in the hypertension mechanism.
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